COLUMBIA — Hilton Head Health System is challenging the state health agency’s decision to deny it permission to build a Bluffton Outpatient Center medical office building.

In correspondence last month with the S.C. Department of Health and Environmental Control, a lawyer for Hilton Head Health System, which does business as Hilton Head Hospital, argues that the objections of its area competitor St. Joseph/Candler health system, “a profitable Georgia hospital system,” should not have factored into the state’s denial of its application because the Georgia system did not have the standing to do so.

The letter, dated Feb. 21, to state regulators followed DHEC’s Feb. 6 denial of the fiercely sought “certificate of need,” or CON, which is granted on a limited basis to projects that meet the qualifications of the State Health Plan. In rejecting the hospital’s application, state regulators said past and projected demand did not support the new facility.

But Hilton Head Health System’s letter also notes that in the past five years, the agency approved seven other applications to build a medical office building and did so without subjecting them the same level of review as the Hilton Head Hospital application.

What’s more, argues the attorney, all but two services — the CT and the nuclear medicine camera — exist already and would simply be relocated to the proposed medical office building.

The agency board is expected to vote on whether to hear Hilton Head Health System’s appeal today.